1. Field of the Invention
The present invention relates to materials used to stop low to high flow water leaks associated with water conveyance and control structures located in hard to access areas and, more particularly, to hydrophilic polyurethane impregnated rubber adapted for this purpose.
2. Related Art
Water conveyance systems typically include large concrete and steel pipes for carrying water to power generators, pumps and water users. Pipes used with water conveyance systems are subject to corrosion and deterioration. Over time, such corrosion and deterioration causes leaks to be formed in the pipes. A number of materials have been developed to repair leaks in conveyance system pipes. However, the repair materials and methods developed in the prior art have not performed satisfactorily for a number of reasons. More specifically, these materials have either failed to adequately seal the leak, are washed away before they are cured, or have become dis-bonded prematurely. Even when these prior art materials stay in place and properly cure, movement of the sealant can cause the sealant to leak.
According to the invention, there is provided an improved material for sealing leaks in water conveyance systems, the material comprising a porous hydrophilic rubber and a polyurethane resin impregnated into the pores of the porous hydrophilic rubber.
The polyurethane resin is preferably a water reactive powder resin and includes toluene diisocyanate, triethylene glycol or hydroximethal propenediol.
The amount of polyurethane resin in the material is preferably between 10% to 90% of the total composition of the material. In a more preferred embodiment, the material comprises 40% polyurethane resin and 60% porous hydrophilic rubber.
Other features and advantages of the invention will be set forth in, or apparent from, the following detailed description of the preferred embodiments of the invention.